Edge Pro and Yanagi

I hope I did not miss a similar thread on this topic, but I searched as thoroughly as I could, yet being a frenchie, I may very well have.

My question is the following: is it possible to sharpen a yanagi on an EP, [b]without reprofiling the blade in the first place [/b]? I will elaborate a little on why I don't see any other solution:

The yanagi blade slowly gets narrower all the way from heel to tip. Therefore, as the spine of the blade moves along the guide of the EP, the angle of the stone with respect to the flat of the blade increases slightly. And this is not a question of keeping the blade parallel to the table, just simple math in a triangle with one edge getting shorter. Although it may not be a problem on, say, a sujihiki, where a few tenths of a degree will go unnoticed as they will result in few microns of edge width, it is a problem on my yanagi: if the stone contacts the full width of the bevel at the heel, it barely grinds the lower millimeter (sorry for the metric system^^) of the bevel at the tip. The reason for this seems to me that the angle of the bevel with respect to the (concave yet almost) flat of the blade is constant, so the variation of the angle of the stone is of consequence when the bevel is more than half an inch wide.

I expect this problem would not arise with an usuba, which has the (almost) same blade width from heel to tip

So here are a few potential conclusions I came up with, but I'm eager to have the advice of people more skilled with yanagis and/or EP as I am:1) Just spend a couple hours reprofiling the yanagi blade to end up with a slightly variable bevel angle that will be matched by the EP stone.2) Keep sharpening my yanagi freehand, as I do with my Suisin Deba and my Ittosai Usuba3) Dump the yanagi for a better one (this is a Global one, and it is far from perfect: the back is not consistently ground, resulting in a variable edge width on the back, it does not retain the edge nearly as well as the two others,...) which would not have this issue, if such a yanagi exists ?

Re: Edge Pro and Yanagi

Wed Aug 22, 2012 5:56 pm

I don't want to come off as having much expertise on the yanagi-meets-the-edge-pro question, but wanted to at least try to be helpful. I have both edge pro and a yanagi, and the two have never met. Why? I have read from several posters (who know loads more than i do on the subject of sharpening and appear to be pros at this) that one should only sharpen the yanagi by hand. Rather than me trying to parrot their logic (which I recall seemed very reasonable), you should continue to look at a few knife sites because i did read several very thoughtful posts on this subject. i would probably at least try to run those posts down before you try it, then can you make your own decision.

Again, look around a bit more, because i know i have seen discussions on this subject. hope that sort of helps.

Re: Edge Pro and Yanagi

Fri Aug 24, 2012 8:03 am

Right. I've taken a look at other forums, and either the bevel was ground flat, or the yanagi had a one millimeter "macrobevel" that in my opinion makes it nothing more than a bulky suji. I guess I will continue freehand, which gives good result for the moment.

I guess it just doesn't do the EP justice to explain how you can use it for single bevel knives, if it is actually mechnaically impossible for it to do a good job on these. It's such a great tool for double bevels that it should be sufficient... worse, it could cast a doubt on the other statements from EdgePro, which are indeed justified.